Low duty cycle device protocol

ABSTRACT

The subject matter disclosed herein relates to a system and method for establishing communication between a low duty cycle device and other devices through a wireless communication network. In one particular implementation, the low duty cycle device may awaken from a hibernating state in synchronization with transmission of messages.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 USC § 119 (e)of U.S. Provisional Patent Application Nos. 60/887,536, filed on Jan.31, 2007; and 60/886,904, filed on Jan. 26, 2007, which are herebyincorporated herein by reference, and is a continuation in part andclaims benefit of priority of U.S. patent application Ser. No.11/766,068, filed on Jun. 20, 2007, which claims priority to U.S.Provisional Patent application No. 60/815,769, filed on Jun. 21, 2006and which is hereby incorporated herein by reference.

BACKGROUND

1. Field

The subject matter disclosed herein relates to communication systems andnetworks including low duty cycle devices.

2. Information

Remote monitoring of operations may include the use of low power and/orbattery-operated, wireless telecommunication devices that monitoroperational status information and transmit operational statusinformation to a remotely situated information-processing device. Here,for example, such operational status may be transmitted via radiofrequency signals as short messages. A telecommunication deviceemploying a power consumption saving technique may not be able tocommunicate with a remotely situated information-processing device ifthe telecommunication device is in a sleep mode in order to conservebattery power.

BRIEF DESCRIPTION OF THE FIGURES

Non-limiting and non-exhaustive features will be described withreference to the following figures, wherein like reference numeralsrefer to like parts throughout the various figures.

FIG. 1 is a schematic diagram of communication network adapted tocommunicate with one or more communication terminals according to oneaspect.

FIG. 2 is a schematic diagram illustrating communication protocol stacksaccording to one implementation.

FIG. 3 is a diagram illustrating a call flow according to one aspect.

FIG. 4 is a diagram illustrating a call flow according to anotheraspect,

FIG. 5 is a schematic diagram of a device capable of communication witha wireless network according to one implementation.

FIG. 6 is diagram illustrating synchronization of scheduling of anawakening of device from a hibernating state for messages transmitted ina wireless communication link according to a particular implementation.

SUMMARY

In one particular implementation, a first device is adapted to awaken inperiods from a hibernating state to enable communication with a wirelesscommunication network. By synchronizing with such periods, a seconddevice may schedule transmission of information in the wirelesscommunication network to the first device during such periods. It shouldbe understood, however, that this is merely one example implementationand that claimed subject matter is not limited to this particularimplementation.

DETAILED DESCRIPTION

Reference throughout this specification to “one example”, “one feature”,“an example” or “one feature” means that a particular feature,structure, or characteristic described in connection with the featureand/or example is included in at least one feature and/or example ofclaimed subject matter. Thus, the appearances of the phrase “in oneexample”, “an example”, “in one feature” or “a feature” in variousplaces throughout this specification are not necessarily all referringto the same feature and/or example. Furthermore, the particularfeatures, structures, or characteristics may be combined in one or moreexamples and/or features.

Methodologies described herein may be implemented by various meansdepending upon applications according to particular features and/orexamples. For example, such methodologies may be implemented inhardware, firmware, software, and/or combinations thereof. In a hardwareimplementation, for example, a processing unit may be implemented withinone or more application specific integrated circuits (ASICs), digitalsignal processors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, micro-controllers, microprocessors,electronic devices, other devices units designed to perform thefunctions described herein, and/or combinations thereof.

Location determination and/or estimation techniques described herein maybe used for various wireless communication networks such as a wirelesswide area network (WWAN), a wireless local area network (WLAN), awireless personal area network (WPAN), and so on. The term “network” and“system” may be used interchangeably herein. A WWAN may comprise, forexample, & Code Division Multiple Access (CDMA) network, a Time DivisionMultiple Access (TDMA) network, a Frequency Division Multiple Access(FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA)network, a Single-Carrier Frequency Division Multiple Access (SC-FDMA)network, and so on, A CDMA network may implement one or more radioaccess technologies (RATs) such as cdma2000, Wideband-CDMA (W-CDMA), toname just a few radio technologies Here, cdma2000 may includetechnologies implemented according to IS-95, IS-2000, and IS-856standards, for example. A TDMA network may implement Global System forMobile Communications (GSM), Digital Advanced Mobile Phone System(D-AMPS), or some other RAT. GSM and W-CDMA are described in documentsfrom a consortium named “3rd Generation Partnership Project” (3GPP).Cdma2000 is described in documents from a consortium named “3rdGeneration Partnership Project 2” (3GPP2). 3GPP and 3GPP2 documents arepublicly available. A WLAN may comprise an IEEE 802.11x network, and aWPAN may comprise a Bluetooth network, an IEEE 802.15x, for example.Such location determination techniques described herein may also be usedfor any combination of WWAN, WLAN and/or WPAN,

According to an example, a device and/or system may estimate itslocation based, at least in part, on signals received from SVs. Inparticular, such a device and/or system may obtain “pseudorange”measurements comprising approximations of distances between associatedSVs and a navigation satellite receiver. In a particular example, such apseudorange may be determined at a receiver that is capable ofprocessing signals from one or more SVs as part of a SatellitePositioning System (SPS). To determine its location, a satellitenavigation receiver may obtain pseudorange measurements to three or moresatellites as well as their positions at time of transmitting.

Techniques described herein may be used with any one of several SPS′.Furthermore, such techniques may be used with positioning determinationsystems that utilize pseudolites or a combination of satellites andpseudolites. Pseudolites may comprise ground-based transmitters thatbroadcast a PN code or other ranging code (e.g., similar to a GPS orCDMA cellular signal) modulated on an L-band (or other frequency)carrier signal, which may be synchronized with time. Such a transmittermay be assigned a unique PN code so as to permit identification by aremote receiver. Pseudolites are useful in situations where GPS signalsfrom an orbiting satellite might be unavailable, such as in tunnels,mines, buildings, urban canyons or other enclosed areas. Anotherimplementation of pseudolites is known as radio-beacons. The term“satellite”, as used herein, is intended to include pseudolites.equivalents of pseudolites and possibly others. The term “SPS signals”,as used herein, is intended to include SPS-like signals from pseudolitesor equivalents of pseudolites.

In one particular implementation, a device may comprise a navigationreceiver may be adapted to receive signals from one or moretransmitters, which are indicative of a location of the navigationreceiver. The device may further include a transceiver which is adaptedto communicate with other devices such as, for example, a server througha wireless communication network. In one aspect, the device may beadapted to intermittently awaken from a hibernated or hibernating statein synchronization with the location server to exchange information withthe location server over the wireless communication network. However,this is merely an example of a particular implementation and claimedsubject matter is not limited in this respect.

While in a hibernating state, a device may operate at a reduced powerand reduced functionality. In one particular example, a device in ahibernating state may not be capable of receiving and/or processingsignals transmitted in a wireless communication network. In anotherimplementation, a device in a hibernating state may sufficiently power atiming feature to track duration of hibernation cycles and/or the likeand initiate an awakening of the device from a hibernating state. Byintermittently awakening from a hibernated state in synchronization witha location server, a device may receive information in a downlinkcommunication channel from a server through a bi-directionalcommunication channel without constantly being in a full power state toreceive signals from a wireless communication network.

FIG. 1 is a schematic diagram of communication network adapted tocommunicate with one or more communication terminals according to oneaspect. Here terminals 102 may comprise any one of several devicesadapted to obtain information relating to its location. Here, a terminal102 may comprise any one of several low-power devices such as, forexample, a device embedded in clothing, a pet collar, mobile telephone,key ring, a shipping container or a transportation vehicle, just to namea few examples. Here, such devices may comprise battery powered devicescapable of operating in a power saving mode to preserve and/or extendbattery life. Terminal 102 may be employed in any one of severalapplications including, for example, asset tracking, automated meterreading, cashless payment of parking meters, traffic lights and sensors,billboards and public displays, real-time health monitoring. home/officesecurity and alarm systems, automotive telematics, utility distributionand grid monitoring, position/location monitoring and/or pollingapplications, just to names few examples.

In one implementation, a terminal 102 may be configured to communicatewith a center 110 and/or application server 114. Here, a center 110 maycomprise any one of several devices and/or processes such as, forexample, a communication server that is adapted to facilitatetransmission of messages between devices in a first communicationnetwork and devices in a second communication network. In one aspect, aterminal 102 may transmit information to a center 110 and/or applicationserver 114 through an uplink portion of a wireless communication linkwith an associated mobile switching center and/or base station subsystem(MSC/BSS) 104. In one particular implementation, such an uplink portionof a wireless communication link may comprise access channels used fortransmission of registration requests, call set up requests, pageresponses, order responses, and/or other information that may berequired by system protocols. Information transmitted to a center 110and/or application server 114 in the uplink portion may include, forexample, status information regarding one or more devices co-locatedwith a terminal 102, sensor data, location information, battery statusand/or the like. In this context, “location information” refers toinformation that may be descriptive of a location, such as an estimateof a location of a terminal 102, and/or information that may be used incomputing such an estimate.

Also, a center 110 and/or application server 114 may transmitinformation to a terminal 102 through a downlink portion of the wirelesscommunication link with the associated MSC/BSS 104. In one particularimplementation, such a downlink portion of a wireless communication linkmay comprise pilot channels providing beacon functionality for initialsystem acquisition, sync channels for carrying system parametersrequired at system acquisition, and paging channels used to carryoverhead messages, pages, setup messages and orders. Informationtransmitted to a terminal 102 in a downlink portion may include, forexample, information to control one or more devices co-located with theterminal 102, commands to control and/or configure the terminal 102and/or the like. As illustrated below, a terminal 102 may from time totime hibernate on intervals of a predetermined cycle. In particularimplementations, such a commands to control and/or configure such aterminal 102 may comprise a command to change a hibernation interval ofsuch a predetermined cycle.

In particular implementations, a center 110 may communicate with aterminal 102 according to a short message system (SMS) protocol. Here,for example, such transmission of messages between a center 110 andterminal 102 according to an SMS protocol may be facilitated by amessage center (MC) 106 and/or mobile positioning center 108, forexample. Information may be transmitted between a center 110 andassociated application server 114 using any one of several communicationprotocols and network communication infrastructure such as, for example,TCP/IP over any Internet Protocol infrastructure Here, an exampleimplementation of protocol stacks for a terminal 102, center 110 andapplication server 114 may be as depicted in FIG. 2 as protocol stacks202, 210 and 214, respectively. In at least one alternativeimplementation, to reduce latencies a center 110 may be adapted tocommunicate directly with an MSC/BSS 104 according to a short messagedelivery point-to-point bearer service (SMDPP). However, these aremerely examples of how a terminal, center and/or application server maycommunicate with one another using particular implementations ofprotocol stacks and claimed subject matter is not limited in theserespects.

In one aspect, a terminal 102 may comprise one or more devices capableof collecting information for use in computing an estimate of a locationof the terminal 102 using any one of several techniques. In oneimplementation, radio frequency (RF) signals received at a receiver (notshown) associated with a terminal 102 may be used to compute an estimateof a location of the terminal 102 using techniques known to those ofskill in the art. Such signals may include, for example, SPS signals.Here, such received SPS signals may be used to determine a pseudorangemeasurements that may be used to compute an estimate of a location, forexample. In other implementations, such received signals may alsoinclude signals received from terrestrial transmitters such as, forexample, transmitters on devices in a WLAN, WPAN and/or WWAN, forexample. Characteristics from these signals such as signal strength,media access control (MAC) addresses, and/or the like may also be usedto compute an estimate of a location.

In one example, although claimed subject matter is not limited in thisrespect, a device (not shown) associated with a terminal 102 may becapable of obtaining pseudorange measurements to transmitters based, atleast in part, on SPS signal received at the device using knowntechniques. Here, such a device may be capable of receiving acquisitionassistance information from another device such as a positiondetermination entity PDE 112 and/or mobile positioning center/PDE(MPC/PDE) 108. In one particular Implementation, such a device mayfurther be capable of estimating Its location based, at least in part,on such pseudorange measurements obtained from received SPS signals.Alternatively, the terminal 102 may forward such pseudorangemeasurements and/or other information derived from received signalsthrough an uplink with an MSC/BSS 104 and to a destination such anestimate a location of the terminal 102 can be computed. For example, anapplication server 114 and/or PDE 112 may determine a location of aterminal 102 based, at least in part, on pseudorange measurements and/orother information received from the terminal 102. It should beunderstood, however, that this is merely on example of how a location ofa device may be estimated according to a particular implementation andclaimed subject matter is not limited in this respect.

FIG. 3 is a diagram illustrating a call flow 300 for an immediate signalrequest for a terminal according to one aspect. Here, at an event 316 anapplication server 314 may initiate a location immediate request. (LIR)message to terminal 302 including, for example, a unique identifierassociated with terminal 302. In response to the LIR message, at event318 center 310 may initiate position request message (PRM) in a call toterminal 302 requesting location information. In response to the PRM, atevent 320 the terminal 302 may respond with a message containinginformation such as, for example, an estimate of the location ofterminal 302 (e.g., as autonomously computed at terminal 302) and/orinformation that may be used in computing such an estimate (e.g.,pseudorange measurements and/or other measurements based, at least inpart on signals received at terminal 302).

At event 326, center 310 may return to application server 314 anestimate of the location of terminal 302 including, for example,information indicative of uncertainty associated with the estimate. Inone alternative, upon receipt of a response message at event 320, center310 may call PDE 312 at an event 322 to request computation of anestimate of the location of terminal 302. Here, such a call to PDE 312may include, for example, information received at event 320 that may beused in provide information that may be used in estimating a location ofterminal 302. Based, at least in part, on such information, PDE 312 maycompute an estimate of the location of terminal 302 along with a measureof uncertainty of the estimate and transmit a message to center 310containing same at event 324 in response to the call from center 310. Ina particular implementation, although claimed subject matter is notlimited in this respect, PDE 312 and center 310 may communicateaccording to any one of several communication protocols such asprotocols implemented according to a SnapTrack™ application programminginterface (SNAPI).

FIG. 4 is a diagram illustrating a call flow 400 for an immediate signalrequest for a terminal according to one aspect. Here, an applicationserver 414 may transmit an MLP message at event 416 as detailed abovewith reference to FIG. 3. In this particular example, however, an MLPmessage transmitted at event 416 may also indicate “reporting criteria.”In one example, such reporting criteria may include a command requestingthat location information associated with terminal 402 be updated fromtime to time. Here, terminal 402 may be configured and/or programmed tohave a “duty cycle” indicating times that terminal 402 may be incommunication with center 410 in a call over a bi-directional wirelesscommunication link, for example. With knowledge of such a duty cycle, atevent 420 center 410 may transmit at an appropriate time a PRM toterminal 402 including, for example, information specifying a particularposition estimation mode to be used (e.g., assisted or unassisted)based, at least in part, on a particular application, QoS, reportingcriteria and/or the like. Here, such reporting criteria may include, forexample, a format and/or frequency for providing location informationregarding terminal 402. Accordingly, following an initial cycle ofproviding such information at events 422 through 428, terminal 402 mayprovide updates of such information from time to time as shown by events430 through 436, for example.

As illustrated above using particular examples, a terminal 102 maycommunicate with a center 110 over a bi-directional communication linkincluding a wireless communication link. In an uplink portion, forexample, terminal 102 may transmit information such as, for example,status information and/or information relating to a location of terminal102, Such information may then be forwarded to an application server114, for example. In a downlink portion of the bi-directionalcommunication link, center 110 may transmit information such as, forexample, configuration commands to terminal 102. As illustrated above,however, terminal 102 may comprise a low duty cycle device which, fromtime to time, may be in a hibernating state to, for example, conservepower. In particular implementations, accordingly, terminal 102 may needto transition to an awakened state to be able to receive informationtransmitted from a center 110 in a downlink portion of a bi-directionalwireless communication link.

As illustrated above, terminal 102 may be adapted to intermittentlyawaken from a hibernated state as, for example, a low duty cycle device.In particular implementations such as in a CDMA network for example,while in an awakened state such a terminal 102 may perform slotted modeoperations such as listening to a paging channel, receiving messages andsending messages. As such, while in an awakened state terminal 102 maytransmit information to a center 110 on an uplink portion of a wirelesscommunication link and/or receive information from a center 110 on anassociated downlink portion. In one particular implementation, althoughclaimed subject matter is not limited in this respect, such a terminal102 may be adapted and/or configured to a wale en from such a hibernatedstate in synchronization with an associated center 110. As such, theassociated center 110 may transmit information to terminal. 102 whileterminal 102 is awakened from a hibernated state and capable ofreceiving information on a downlink portion of a wireless communicationlink.

In one implementation, a terminal 102 may register with a wirelesscommunication network by, for example, acquiring a signal from a nearbyMSC/BSS 104, and exchanging information using techniques similar tothose used for registering devices joining a CDMA network, for example.As part of such a registration, terminal 102 may indicate attributessuch as, for example, identification information, information indicatingparticular capabilities of terminal 102 such as battery capacity andremaining battery life, information specifying a hibernation duty cycle(e.g., time between consecutive wake ups I_(HI) and/or the duration ofbeing in an awakened state in any one cycle) In one particular example,such information specifying battery capacity and/or remaining batterylife may enable an application server 114 to compute an appropriatehibernation interval for the terminal 102 (e.g., longer hibernationintervals if the battery is weak or has low capacity) and/or configureterminal 102 according to appropriate times between wake-up events andduration intervals for terminal 102 to be in an awakened state. Suchinformation may also be used for triggering messages to a remote user(e.g., via SMS messages) notifying the remote user that the batter) isgetting low and needs to be replaced or recharged

In one implementation, following registration, terminal 102 may beplaced in an idle but awakened state for a defined duration to receivemessages from a downlink portion of a communication link. During thisduration, for example, a center 110 may forward any pending messagesaddressed to the resistered terminal 102 and received at center 110(e.g., from an application server 114) prior to registration.

In another implementation, in response registration of the terminal 102with the network, a center 110 may transmit a configuration message tothe registered terminal 102. Such a configuration message may includeinformation such as, for example, T_(BEGIN) (time at which terminal 102is permitted to begin unsolicited messaging) and/or T_(END) (time afterwhich terminal 102 is not permitted to send any more messages).Accordingly, with knowledge of I_(HI), I_(BEGIN) and T_(END), periods ofterminal 102 in an awakened state may be synchronized with a center 110to receive downlink messages as pointed out above. During such a periodwhen terminal 102 is in an awakened state, for example, the center 110may forward in a downlink portion of a wireless communication linkmessages including pending messages and/or commands addressed to theterminal 102 (e.g., from an application server 114).

In yet another implementation, a terminal 102 may transmit anunscheduled and unsolicited message to a center 110 to indicate that theterminal is in an awakened state for a duration during which theterminal 102 may receive downlink messages. In response to such anunsolicited message, the center 110 may locate and obtain pendingmessages that are addressed to the terminal 102 and forward thesemessages in a downlink portion of a wireless communication link asillustrated above.

In one example, a terminal 102 may lose synchronization with a center110. In one particular implementation, a terminal 102 may be adapted totransmit a “keep alive” message to the center at intervals. Here, such akeep alive message may include information such as, for example,information provided in a registration message, for example.

In particular implementations, a center 110 may schedule messages fortransmission to a terminal 102. For example, a center 110 may storemessages addressed to a terminal in a data structure that permitstransmission through an associated MSC/BSS 104 during periods in which arecipient terminal 102 is in an awakened state and capable of receivingmessages from a downlink portion of a wireless communication link. Acenter 110 may schedule downlink messages to be forwarded by aparticular MSC/BSS 104 on regular scheduling intervals. For example, acenter 110 may select a particular scheduling interval for transmissionof a downlink; message through an MSC/BSS 104 to a terminal 102 tosynchronize transmission of the downlink, message during a subsequentperiod in which the terminal 102 is In an awakened slate. Accordingly,the recipient terminal 102 may be adapted to intermittently awaken froma hibernating state in synchronization with a center 110 to receivedownlink messages.

In one particular implementation, a center 110 may schedule suchdownlink messages in a particular scheduling interval based, at least inpart, on an average delay T_(MIN) _(—) _(MSC) _(—) _(DELAY) intransmission of a downlink message from the associated MSC/BSS 104following receipt of such a messages from the center 110. Here, thecenter 110 may forward messages to an associated MSC/BSS 104 at T_(MIN)_(—) _(MSC) _(—) _(DELAY) prior to scheduled transmission to a terminal102 by, for example, passing the messages to an appropriate applicationand/or transport layer (e.g., in protocol stack 210).

As illustrated elsewhere herein, a terminal 102 may be adapted tocommunicate with an associated MSC/BSS in a wireless communication linkaccording to a CDMA protocol In this particular implementation,following a boot sequence and registration as discussed above, aterminal 102 may be placed in a slotted mode where a wake up time may bedetermined as follows:

${WAKEUP\_ TIME} = \left\lbrack {{T_{HI}*\left\lfloor \frac{{CDMA\_ SYSTEM}{\_ TIME}}{T_{HI}} \right\rfloor} + \left( T_{OFFSET} \right)} \right\rbrack$WAKEUP_TIME=T_(HI)*(CDMA_SYSTEM_TME/T_(HI))'T_(OFFSET)

if WAKEUP_TIME≧CDMA_SYSTEM_TIME; and

WAKEUP_TIME=T_(HI)*(CDMA_SYSTEM_TME/T_(HI))'T_(OFFSET)+T_(HI)

if WAKEUP_TIME<CDMA_SYSTEM_TIME.

Where TOFFSET may be determined using a hash as follows;

$T_{OFFSET} = \left\lfloor \frac{N*\left\lbrack {\left\lbrack {2654435769 \star {ESN}} \right\rbrack {MOD}\; 2^{32}} \right\rbrack}{2^{32}} \right\rfloor$

-   -   N is an integer value expression of T_(HI) in seconds; and    -   ESN is 32-bit expression.

Synchronous scheduling 600 as used in one implementation is illustratedin FIG. 6. Shown are timelines Illustrating for a center 110 and aterminal 102. It will be appreciated that FIG. 6 depicts timelines for asingle center 110 and a single terminal 102, and that, particularimplementations may provide for at least one center 110 and a pluralityof terminals 102. A wake up time 605 for the terminal. 102 based, atleast in part, on T_(BEGIN) has been hashed and is known to both center110 and terminal 102. The center 110 may have received messages (e.g.,from an AS 114) for transmission to the terminal 102, which have beenstored and sorted in a memory (not shown) according to a destinationassociated with terminal 102 and time of future transmission. Atsubstantially wake up time 605 the center 110 may initiate transmissionof a message at time 615 Including any stored messages for transmissionto the terminal 102. Such a message is received at time 620 by theterminal 102. A responsive message may be received by the center 110from the terminal 102. Before transition to hibernation at time 610 isreached, the terminal 102 may transmit one or more messages to center110 received at time 632. In the particular illustration of FIG. 6,receipt of such messages by center 110 occurs at time 632 prior totransition to hibernation at time 610. It should be understood, however,that in other scenarios center 110 may actually receive such messagesafter such a transition of the terminal 102 to hibernation. Such amessage may comprise, for example, a KA message including informationregarding operational status, battery status, network information, and arequest for configuration data. In one implementation, after T_(END)occurs and the terminal 102 is regarded as being in a hibernating state,the center 110 at time 640 may select pending messages for transmissionto the terminal 102 the next transmission time, coinciding with thesubsequent period in which terminal 102 transitions to an awakenedstate. While FIG. 6 shows merely one time 640 during a

hibernation interval at which the center 11.0 may select pendingmessages for transmission, it should be understood that the center maymake such a selection at multiple times during such a hibernationinterval. At substantially the next, awakening at time 642, the center110 may initiate transmission of pending messages to the terminal 102,after which the center 110 receives at time 650 a message from theterminal 102. At time 632, the center 110 may continue to receivemessages such as KA messages depending upon an amount of time leftbefore transition back to a hibernating state 652. In anotherimplementation, transitions between a hibernating state and awakenedstate at times 610 and 652 may be dynamically adjusted according to thenumber and nature of the messages sent and received by center 110 fortransmission to terminal 102. For example, if the number of pendingmessages is too large to be carried by a single SMS message transmittedat times 615 or 645, then only a portion will be transmitted at thesetimes. Upon receiving messages at times 630 and 650, the center 110 maythen reset and extend transitions to a hibernating state at times 610and 652. A center 110 may then send (not shown) a subsequent portionand/or remainder of the pending messages in a similar manner. Thisprocess may be continued until all of the pending messages addressed toterminal 102 are transmitted by the center 110.

In one particular implementation, synchronization and/or timing betweena center 110 and a terminal 102 may be substantially de-coupled fromtiming of transmission of uplink and downlink messages in a wirelesscommunication link. Referring again to protocol stacks 202 and 210,illustrating communication between a center 110 and terminal 102 in oneimplementation, SMS messages may be transmitted between communicationlayers of respective center 110 and terminal 102 without regard tomessage timing on uplink and downlink messages. In one particularimplementation, SMS messages may be transmitted be transmitted between amessage center 106 and center 110 in data packets over Internet Protocolinfrastructure. Thus, center 110 may schedule messages and/or periodswhen terminal 102 is hibernating or awake independently of the timing ofmessages transmitted in the uplink and downlink portions betweenterminal 102 and an MSC/BSS 104. Accordingly, a center 110 may begeographically decoupled and/or removed from a cellular network andplaced elsewhere for more convenient access by a party who communicateswith terminal 102.

In one implementation as discussed above, a center 110 may determine alength of a duration in which a terminal 102 is in an awakened state inany one cycle. The center 110 may set this duration by, for example,specifying such a duration in one or more configuration messagestransmitted to the terminal 102. In another Implementation, a center 110may determine such a duration based, at least in part, on an uncertaintyassociated with the average delay T_(MIN) _(—) _(MSC) _(—) _(DELAY) intransmission of a downlink message from an associated MSC/BSS 104following receipt of such a messages from the center 110. Here, forexample, if the uncertainty associated with T_(MIN) _(—) _(MSC) _(—)_(DELAY) increases, the center 110 may increase the duration in which aterminal 102 is in an awakened state in any one cycle to ensure that theterminal 102 will be in an awakened state to received messages.Likewise, if the uncertainly associated with T_(MIN) _(—) _(MSC) _(—)_(DELAY) delay decreases, the center 110 may decrease this duration.Here, it should be understood that decreasing the duration in which aterminal 102 Is in an awakened state may be advantageous to increasinglongevity of a batter powering operation of the terminal 102,

In one implementation, although claimed subject matter is not limited inthis respect, the average delay T_(MIN) _(—) _(MSC) _(—) _(DELAY) intransmission of a downlink message may be determined based, at least inpart, upon round-trip message times (e.g., difference between time 615and 630, or between 645 and 650 as shown in FIG. 6). Similarly, anuncertainty in the actual delay of this transmission may be determinedfrom a variance about the average delay T_(MIN) _(—) _(MSC) _(—)_(DELAY).

In a particular implementation, a terminal 102 may comprise a device asshown in FIG. 5, which is capable of processing SPS signals received atan antenna 1414 for determining pseudorange measurements andcommunicating with a wireless communication network through antenna1410. Here, a radio transceiver 1406 may be adapted to modulate an RFcarrier signal with baseband information, such as data, voice and/or SMSmessages, onto an RF carrier, and demodulate a modulated RF carrier toobtain such baseband information. Antenna 1410 may be adapted totransmit a modulated RF carrier over a wireless communications link andreceive a modulated RF carrier over a wireless communications link.

Baseband processor 1408 may be adapted to provide baseband informationfrom CPU 1402 to transceiver 1405 for transmission over a wirelesscommunications link. Here, CPU 1402 may obtain such baseband informationfrom a local interface 1416 which may include, for example,environmental sensory data, motion sensor data, altitude data,acceleration information (e.g., from an accelerometer), proximity toother networks (e.g., ZigBee, Bluetooth, WiFi, peer-to-peer). Suchbaseband information may also include location information such as, forexample, an estimate of a location of device 1400 and/or informationthat may be used in computing same such as, for example, pseudorangemeasurements.

SPS receiver (SPS Rx) 1412 may be adapted to receive and demodulatetransmissions from SVs, and provide demodulated information tocorrelator 1418. Correlator 1418 may be adapted to derive correlationfunctions from the information provided by receiver 1412. Correlator1418 may also be adapted to derived pilot-related correlation functionsfrom information relating to pilot signals provided by transceiver 1406.This information may be used by device acquire a wireless communicationsnetwork.

Channel decoder 1420 may be adapted to decode channel symbols receivedfrom baseband processor 1408 into underlying source bits. In one examplewhere channel symbols comprise convolutionally encoded symbols, such achannel decoder may comprise a Viterbi decoder. In a second example,where channel symbols comprise serial or parallel concatenations ofconvolutional codes, channel decoder 1420 may comprise a turbo decoder.

Memory 1404 may be adapted to store machine-readable instructions whichare executable to perform one or more of processes, examples,implementations, or examples thereof which have been described orsuggested. CPU 1402 may be adapted to access and execute suchmachine-readable instructions. However, these are merely examples oftasks that may be performed by a CPU In a particular aspect and claimedsubject matter in not limited in these respects,

While there has been illustrated and described what are presentlyconsidered to be example features, it will be understood by thoseskilled in the art that various other modifications may be made, andequivalents may be substituted, without departing from claimed subjectmatter. Additionally, many modifications may be made to adapt aparticular situation to the teachings of claimed subject matter withoutdeparting from, the central concept described herein. Therefore, it isintended that claimed subject matter not be limited to the particularexamples disclosed, but that such claimed subject matter may alsoinclude all aspects falling within the scope of appended claims, andequivalents thereof. One or more claims may recite a feature in the form“A or B, or both” to specify that such a feature may includeelement/limitation “A” or element/limitation “B”, or bothelement/limitation “A” and element/limitation “B”. Furthermore, such afeature recited in the form “A or B, or both” is not to exclude thepresence of elements in addition to element/limitation “A” orelement/limitation “B”.

1. A device comprising: a receiver adapted to receive signals from oneor more transmitters; and a transceiver adapted to communicate with aserver through a wireless communication network, wherein said device isadapted to intermittently awaken from a hibernating state insynchronization with said server to exchange information with saidserver over said wireless communication network, said informationincluding location information which is based, at least in part, on saidreceived signals.
 2. The device of claim 1, wherein said device isadapted to bi-directionally exchange said information using a shortmessage service (SMS).
 3. The device of claim 1, wherein said locationinformation comprises pseudorange measurements determined based, atleast in part, on said received signals.
 4. The device of claim 3,wherein said information further comprises information selected from thegroup consisting essentially of almanac Information and ephemerisinformation associated with a satellite positioning system (SPS).
 5. Thedevice of claim 1, wherein said transceiver is adapted to transmitinformation to or receive information from said wireless communicationnetwork, or both, according to a code division multiple access protocol.6. The device of claim 1, wherein said device is adapted to awaken fromsaid hibernating state according to a predetermined schedule.
 7. Thedevice of claim 1, wherein said information further includes commandsissued to said device from said server.
 8. The device of claim 1,wherein said information comprises an estimate of a location of saiddevice based, at least in part, on said received signals.
 9. The deviceof claim 1, wherein said device is further adapted to transmitenvironmental sensor data to said server through said wirelesscommunication network.
 10. A method comprising: receiving signals at areceiver; intermittently awakening a first device from a hibernatingstate in synchronization with a second to exchange information with saidsecond device server over a wireless communication network, saidinformation including location information which is based, at least inpart, on said received signals.
 11. The method of claim 10, and furthercomprising exchanging said information using a short message service(SMS).
 12. The method of claim 10, wherein said location informationcomprises pseudorange measurements determined based, at least in part,on said received signals.
 13. The method of claim 12, wherein saidinformation is selected from the group comprising essentially of almanacinformation and ephemeris information associated with a satellitepositioning system (SPS).
 14. The method of claim 10, wherein saidinformation is transmitted to said wireless communication network,received from said wireless communication network, or both, according toa code division multiple access protocol.
 15. The method of claim 10,wherein said intermittently awakening said device from said hibernatingstate comprises awakening said device from said hibernating stateaccording to a predetermined schedule.
 16. The method of claim 10,wherein said information further includes commands issued to said devicefrom said server.
 17. The method of claim 10, wherein said informationcomprises an estimate of a location of said device based, at least inpart, on said received signals.
 18. The method of claim 10, wherein saiddevice is further adapted to transmit environmental sensor data to saidserver through said wireless communication network.
 19. An articlecomprising: a storage medium comprising machine-readable instructionsstored thereon which, if executed by a computing platform, are adaptedto cause said computing platform to: process signals received at areceiver; and intermittently awaken a first device from a hibernatingstate in synchronization with a second to exchange information with saidsecond device server over a wireless communication network, saidinformation including location information which is based, at least inpart, on said processed signals.
 20. The article of claim 19, whereinsaid instructions, if executed by said computing platform, are furtheradapted to cause said computing platform to intermittently awaken saiddevice from said hibernating according to a predetermined schedule. 21.The article of claim 19, wherein said instructions, if executed by saidcomputing platform, are further adapted to initiate exchange of saidinformation using a short message service (SMS).
 22. The article ofclaim 19, wherein said location information comprises pseudorangemeasurements determined based, at least in part, on said receivedsignals.
 23. An apparatus comprising: means for processing signalsreceived at a receiver; and means for intermittently awakening a firstdevice from a hibernating state in synchronization with a second toexchange information, with said second device over a wirelesscommunication network, said information including location informationwhich is based, at least in part, on said processed signals.
 24. Theapparatus of claim 23, wherein said means for intermittently awakeningsaid first device further comprises means for intermittently awakeningsaid first device from said hibernating according to a predeterminedschedule,
 25. The apparatus of claim 23, and further comprising meansfor initiating exchange of said information with said second deviceusing a short message service (SMS).
 26. The apparatus of claim 23,wherein said location information comprises pseudorange measurementsdetermined based, at least in part, on said received signals.
 27. Amethod comprising: receiving messages addressed to a device; andscheduling transmission of said messages to said device through adownlink portion of a wireless communication link during intervals inwhich said device is awakened from a hibernating state.
 28. The methodof claim 27, and further comprising: receiving information from saiddevice indicating a hibernation duty cycle; and scheduling saidtransmission based, at least in part, on said information.
 29. Themethod of claim 28, wherein said information is transmitted from saiddevice during a procedure to register said device with a wirelesscommunication network.
 30. The method of claim 27, wherein said messagesare transmitted according to a short message service (SMS) protocol. 31.The method of claim 27, wherein said scheduling said transmission ofmessages comprises scheduling said messages independently of the timingof transmission of messages in said downlink portion.
 32. The method ofclaim 27, and further comprising: defining an interval for periods inwhich said device in an awakened state; and scheduling transmission of amessage to indicate such defined interval.
 33. The method of claim 32,wherein said defining said interval comprises changing said intervalbased, at least in part, on a battery level associated with the device.34. The method of claim 27, wherein said defining said intervalcomprises defining said interval based, at least in part, on anuncertainty associated with a delay between transmission of saidmessages and receipt at said device from said downlink.
 35. An articlecomprising: a storage medium having machine-readable instructions storedthereon which, if executed by a computing platform, are adapted to causesaid computing platform to store messages addressed to a device in adata structure; and schedule transmission of said messages to saiddevice through a downlink portion of a wireless communication linkduring intervals in which said device is awakened from a hibernatingstate.
 36. The article of claim 35, wherein said machine-readableinstructions, if executed, are further adapted to cause said computingplatform to: schedule said transmission based, at least in part, oninformation received from said device indicating a hibernation dutycycle.
 37. The article of claim 35, wherein said instructions., ifexecuted, are further adapted to cause said computing platform toschedule said messages independently of the timing of transmission ofmessages in said downlink portion.
 38. The article of claim 35, whereinsaid instructions, if executed, are further adapted to cause saidcomputing platform to: define an interval for periods in which saiddevice in an awakened state; and schedule transmission of a message toindicate such defined interval.
 39. The article of claim 37, whereinsaid instructions, if executed, are further adapted to cause saidcomputing platform to change said interval based, at least in part, on abattery level associated with the device.
 40. The article of claim 35,wherein said instructions, if executed, are further adapted to causesaid computing platform to define said interval based, at least in part,on an uncertainty associated with a delay between transmission of saidmessages and receipt at said device from said downlink.
 41. An apparatuscomprising: a computing platform, said computing platform being adaptedto: store messages addressed to a device in a data structure; andschedule transmission of said messages to said device through a downlinkportion of a wireless communication link during intervals in which saiddevice is awakened from a hibernating state.
 42. The apparatus of claim41, wherein said computing platform is further adapted to: schedule saidtransmission based, at least in part, on said information. Indicating ahibernation duty cycle.
 43. The apparatus of claim 41, wherein saidcomputing platform is further adapted to: schedule transmission of saidmessages independently of the timing of transmission of said messages insaid downlink portion.
 44. The method of claim 41, and furthercomprising: defining an interval for periods in which said device in anawakened state; and scheduling transmission of a message to indicatesuch defined interval.
 45. The method of claim 44, wherein said definingsaid interval comprises changing said interval based, at least in part,on a battery level associated with the device.
 46. The method of claim41, wherein said defining said interval comprises defining said intervalbased, at least in part, on an uncertainty associated with a delaybetween initiating transmission of said messages and receipt at saiddevice from said downlink.
 47. An apparatus comprising; means forreceiving messages addressed to a device; and means for schedulingtransmission of said messages to said device through a downlink portionof a wireless communication link during intervals in which said deviceis awakened from a hibernating state.
 48. The apparatus of claim 47, andfurther comprising: means for receiving information from said deviceindicating a hibernation duty cycle, and means for scheduling saidtransmission based, at least in part, on said information.
 49. Theapparatus of claim 47, wherein said means for scheduling saidtransmission of messages comprises means for scheduling said messagesindependently of the timing of transmission of messages
 50. Theapparatus of claim 47, and further comprising: means for defining aninterval for periods in which said device in an awakened state; andmeans for scheduling transmission of a message to indicate such definedinterval.
 51. The apparatus of claim 50, wherein said means for definingsaid interval comprises means for changing said interval based, at leastin part, on a battery level associated with the device.
 52. Theapparatus of claim 47, wherein said means for defining said intervalcomprises means for defining said interval based, at least in part, onan uncertainty associated with a delay between initiating transmissionof said messages and receipt at said device from said downlink.